Damper for warm-air furnaces



March 25,1930.

R. s. McNANEY 1,751,830

DAMPER FOR WARM AIR FURNACES Filed Oct. 22, 1928 INVENTOR ATTORNEYJ Patented Mar. 25, 1930 UNITED STATES "PAT r nses snrorrics RALPH s. MCNANEY, or DOWAGIAO, MICHIGAN, Assreuor. TO nowAeIAc STEEL FURNACE COMPANY, or DOWAGIAC, MICHIGAN, A oonPoaA'rIoN or MICHIGAN DAMPER FOR WARM-AIR} FURNACES Application filed October 22, 1928. Serial No. 314,232.

The invention relates to warm air furnaces and more particularly to a construction of direct draft damper arranged in the radiator between the combustion chamber and the smoke fiue.

One of the objects of the invention is to improve the radiator construction to provide for proper baffling of the flue gases to obtain the maximum efiiciency.

Another object is to provide a direct draft damper operable from outside the radiator and so constructed and arranged that the radiator is gas-tight where the operating rod passes therethrough.

A further object is to provide a composite construction formed of sheet metal and cast metal parts welded together to form a substantially seamless construction and provided with special means for eliminating leakage around the damper operating mechanism.

These and other objects are attained by providing the novel construction hereinafter more fully described and illustrated in the accompanying drawings wherein Figure 1 is a central longitudinal section through the furnace;

Figure 2 is an enlarged section through the damper operating mechanism;

Figure 3 is a section on the line 3-3 of Figure 2.

In the construction illustrated in the drawings, the fire pot and combustion chamber of the furnace is formed by a sheet steel drum 10 having a dome-shaped head 11 electrically welded thereto and having a fire door exten sion 15. The particular construction of the fire pot forms no part of the present invention, and will not be described in detail as it is more fully set forth in my co-pending application, Serial No. 314,209 filed'on even date herewith.

23 represents the radiator of the furnace which consists of a segmental body portion 35, having upper and lower heads 36 and 37 i welded thereto. For joining the radiator to the combustion chamber there are two cast metal collars 24 and 25, each of which is flanged at 30 in order that they may be de tachably united by bolts 31. The collars 24 and 25 are constructed of caststeel to enable them to be welded to the sheet'steel radiator and drum, respectively, thereby forming a' strong, seamless construction. A liner 32 of cast iron is inserted within the collars to protect the latter from the hot products of combustion.

WVithin'the radiator 23 is a baffle or detion to extend from a point closely adjacent the inner wall and near the lower end of the radiator to the top of the radiator near the middle thereof. The baffle 40 is also a curved section so that its opposite edges are adjacent .to the outer wall of the drum, thereby causing the gaseous product which passes from a the drum '10 into the radiator 23 to be deflected to the opposite sides thereof and downward and then upward through the center of the drumto the escape fine 38. To permit of direct draft when firing the furna'ce and thereby prevent the products of combustion from escaping into the basement 1 area through the feed door, there is a damper 41 located in an opening in the 'bafileiwhich is in alignment with the nipple or collar24 and flue 38. This damper is hinged at 42 and is weighted so as to automatically close by gravity; In case of a sudden explosion of combustible gases in the drum 10, the damper 41 can automatically swing open and allow the gases to pass directly into and through flue 38, ratherthan pursue their'regular course downward and then upward around baffle 40 with a possibility of blowing open door on clean-out 39 and distributing soot,

to prevent the products of combustion from finding their way out into the casing area. The bearing 45 in which the rock shaft is ournaled is preferably formed of cast steel in order that it may be welded to the sheet steel radiator and thus make a tight joint. The

bearing 45 has a flange 46 the underside of .flector plate 40 arrangedin an inclined posi- LCD which is welded to the head 36 of the radiator. The top face of the flange has a series of raised rings 47 with annular recesses 48 therebetween into which is fitted a complementary part 49 with a series of rings 50 arranged in the recesses 48. Ihe part 47 is fixed to the rock shaft 43 by a set screw 51 and is provided with a lever 52 for actuating the rock shaft and adjusting thedamper. A red 53 extends from the lever to the front of the furnace and provides a convenient handle for opening the damper before opening the fire door. While the bearing 45 is of cast steel, the cooperating part 47 is pref erably of cast iron since it does not require welding. Leakage through the damper operating means is effectively prevented by reason of the large number of bearing surfaces formed by the concentric rings 47 and 50 and by the close contact of the bearing member 45 and the washer 43 WVhat I claim as my invention is:

1. In a furnace, a sheet metal radiator, a damper therein, operating means for said damper extending through said radiator and a bearing of cast metal having substantially the same expansion coefiicient as said sheet metal and Welded thereto.

2. In a furnace, a radiator, a hollow bear ing integrally united thereto, a head on said bearing provided with a series of concentric ringsand intermediate recesses, a shaft extending through said bearing and a cap for said shaft comprising rings engaging the recesses 1n sald head.

3. In a furnace, a steel radiator, a hollow cast steel bearing welded to said radiator, a

rod extending through said bearing, a lug on said rod seating against one end of said bearing, the other end of said bearing having raised rings thereon with intermediate annular recesses and a cap secured to said rod and having complementary rings engaging the recesses of said head, thereby forming a tight joint.

4. In a furnace, a sheet steel radiator, a baffle therein, a direct draft damper in said baflle, a rotatable rod for operating said damper having one end projecting through said radiator, a cast steel bearing for said rod welded to said radiator, a collar on said rod engaging the inner end of said bearing, a cap secured to said rod outside of said radiator, said cap having a series of annular flanges with intermediate recesses and a head on said cast steel bearing having complementary annular flanges and recesses cooperating with said cap to form a leak-proof joint.

. In testimony whereof I affix my signature.

RALPH S. MGNANEY. 

